JPH06252631A - Tri-plate type plane antenna - Google Patents

Abstract

PURPOSE:To obtain an excellent characteristic even at a high frequency band such as a millimeter wave band by providing idle holes to parts corresponding to slots of a ground conductor and radiation elements having two dielectric bodies inbetween. CONSTITUTION:The tri-plate planar antenna is formed by laminating a ground conductor 1, a feeding board 3 on which plural radiation elements 5 and feeders 6 are formed on the face of the conductor 1 via a dielectric body 2, and a ground conductor 4 having plural slots 7 via a dielectric body 2' on the face of the board 4. Then they are arranged so that each slot 7 comes just above the radiation elements 5. Thus, idle holes 8 are provided to parts of the dielectric bodies 2, 2' corresponding to the radiation elements 5 and the slots 7. Thus, even when high density dielectric sheets with high size accuracy are employed for the dielectric bodies 2, 2', broad band and high gain nearly equal to the case of the specific dielectric constant epsilongamma to be 1.0 are obtained as characteristics of the radiation elements 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a triplate type planar antenna used for transmission and reception in a microwave band and a millimeter wave band.

[0002]

2. Description of the Related Art As a means for improving the antenna efficiency of a plane antenna, there is a method of reducing the loss of a feed line by using a triplate line. The basic configuration of this type of antenna is
As shown in FIG. 6, a feeding substrate 3 having a radiation element 5 and a feeding line 6 formed on a surface of a ground conductor 1 via a dielectric 2 is installed, and a dielectric 2'is placed on the surface. The ground conductor 4 having the slot 7 is formed so that the slot 7 is directly above the radiating element 5. Since the antenna of this configuration has a triplate line configuration in which the upper and lower sides of the feed line 6 are shielded by the ground conductor 4 and the ground conductor 1, it is possible to suppress unnecessary radiation from a discontinuous portion such as a bend or a branch portion of the feed line. For,
It is useful as a method of constructing a highly efficient planar antenna that the 1991 Spring Conference of the Institute of Electronics, Information and Communication Engineers B-
102, B-103, the present inventors have already disclosed. Further, in such a triplate type planar antenna, when an antenna having a usable frequency of about 12 GHz is constructed for satellite broadcasting reception, the dielectric material 2 and the dielectric material 2'are foamed with a relative dielectric constant εr of about 1.1. Using a dielectric,
By setting the thickness to about 0.08 times the free space wavelength λ ₀ of the used frequency, it is often the case that a good radiation characteristic with a wide band and high efficiency is realized.

[0003]

On the other hand, in the case of realizing a millimeter-wave band antenna in such a triplate-type planar antenna, for example, when the frequency used is 60 GHz, the antenna can be converted into a simple wavelength as compared with the case of 12 GHz. Will be scaled down to 1/5
The thickness of the dielectric 2 and the dielectric 2'is also extremely thin. Further, the dimensional accuracy required to keep the electric characteristics of the antenna stable is also required to be higher. Therefore, when constructing an antenna in a higher frequency band such as a millimeter wave band, it becomes difficult to use a low-density dielectric material such as a conventional foamed dielectric material as the dielectric material 2 and the dielectric material 2 ', and it is difficult The use of dense dielectric sheets becomes essential.
For this reason, the dielectric constants εr of the dielectric 2 and the dielectric 2'become high, so that the element gain is reduced and the band is narrowed. Further, the propagation wavelength of the parallel plate mode is affected, and the radiating element 5 and the slot There is a problem that the appropriate arrangement interval P of 7 becomes small and the physical space for forming the power supply line 6 is severely restricted.

The present invention provides a triplate type planar antenna which can realize good characteristics even in a higher frequency band such as a millimeter wave band.

[0005]

As shown in FIG. 1, a triplate type planar antenna according to the present invention includes a ground conductor 1 and a plurality of radiating elements 5 on a surface of the ground conductor 1 with a dielectric 2 interposed therebetween. And a feed substrate 3 on which a feed line 6 is formed, and a ground conductor 4 having a plurality of slots 7 are superposed on the surface of the feed substrate 3 so that each slot 7 is directly above the radiating element 5. In the triplate-type planar antenna arranged in the above, the radiating element 5 and the slot 7 of the dielectric 2 and the dielectric 2'are provided.
1 is characterized in that a hole 8 is provided in a portion corresponding to the shape of the radiating element 5, the slot 7 and the hole 8 in FIG. Can be used.

[0006]

By providing the holes 8 in the portions of the dielectric 2 and the dielectric 2'corresponding to the radiating element 5 and the slot 7, the dielectric 2 and the dielectric 2'has a relatively high density with high dimensional accuracy. Even if such a dielectric sheet is used, the characteristics of the radiating element 5 can be obtained with a wide band and a high gain which are almost the same as those when the relative permittivity εr is 1.0. Furthermore, the influence of the dielectric sheet on the propagation wavelength of the parallel plate mode is also alleviated, and the arrangement interval is almost the same as the proper arrangement interval 0.9λ ₀ when using the foamed dielectric having a relative permittivity εr of about 1.1. Good characteristics can be obtained.

[0007]

FIG. 2 shows an embodiment of the present invention. In this configuration, an aluminum plate having a thickness of 1 mm is used as the ground conductor 1.
A film in which a Teflon sheet having a thickness of 0.5 mm and a relative permittivity of about 2.1 is used as the dielectric 2 and the dielectric 2 ′, and a polyimide film having a thickness of 25 μm is bonded to a copper foil having a thickness of 18 μm as the power supply substrate 3. As the base conductor, an aluminum plate having a thickness of 0.3 mm was used. A square hole 8 having a side length of 0.6 times the free space wavelength λ _{0 at} a frequency of use of 60 GHz is provided in a portion of the dielectric 2 and the dielectric 2 ′ corresponding to the radiating element 5 and the slot 7. It was Further, on the feeding substrate 3, the square radiating element 5 and the feeding line 6 each side of which is 0.38 times λ ₀ are formed by etching. Further, in the portion of the ground conductor 4 directly above the radiating element 5, a square slot 7 having a side of 0.6 times λ ₀ is formed.
Was formed. Further, the array interval of the radiating element 5 and the slot 7 was set to 0.9 times λ ₀ to form a 16-element array.
The return loss characteristics of this 16-element array are shown in FIG. 3, gain / efficiency in FIG. 4, and radiation pattern in FIG. 6
It can be seen that good characteristics with wide band and high efficiency are obtained at an extremely high frequency of 0 GHz.

[0008]

As described above, according to the present invention, the dielectric plate 2 and the dielectric 2'of the tri-plate type planar aluminum are relatively dense and have high dimensional accuracy as the frequency used increases. Even if you use
It is possible to provide a triplate-type planar antenna having high efficiency and good antenna characteristics.

[Brief description of drawings]

FIG. 1 is a perspective exploded view showing an embodiment of the present invention.

2A is a top perspective view of an embodiment of the present invention, and FIG. 2B is a sectional view of FIG.

FIG. 3 is a diagram showing a frequency-return loss characteristic of an example of the present invention.

FIG. 4 is a table showing characteristics of an example of the present invention.

FIG. 5 is a diagram showing a relative gain-angle characteristic of one embodiment of the present invention.

FIG. 6 is a perspective exploded view showing a conventional example.

[Explanation of symbols]

1. Ground conductor 2, 2 '. Dielectric 3. Power supply board 4. Ground conductor 5. Radiating element 6. Power supply line 7. Slot 8. Vacancy

Claims (1)

[Claims] 1. A ground conductor 1, a feeding board 3 having a plurality of radiating elements 5 and a feeding line 6 formed on the surface of the ground conductor 1 with a dielectric 2 interposed therebetween, and a dielectric 2'on the surface. In the tri-plate type planar antenna in which the ground conductor 4 having a plurality of slots 7 is overlapped with each other and each slot 7 is arranged right above the radiating element 5, the dielectric 2 and the dielectric 2 '
The holes 8 are formed in the portions corresponding to the radiating element 5 and the slot 7 of
A triplate-type planar antenna characterized by being provided with.